You can find the train schedules (and prices) for any trip within Switzerland on the Swiss railways timetable here: https://www.myswissalp s.com/timetable. The first price you see is the Swiss Half Fare Card price so double it for the regular fare.

When you say Swiss rail pass do you mean the Swiss Travel Pass?

You can find out the discounts given by the Swiss Travel Pass here: https://www.myswissalp s.com/swisstravelpass/ validity. The trip as far as Wengen or Grindelwald is free but then you must buy a ticket for the rest of the trip to Jungfraujoch (you get 25% off the ticket price with your Swiss Travel Pass).